Sprint Car Tire Management

1/11This mountain of tires is what this team feels is required to campaign their USAC/CRA non-wing Sprint car. This is a sizeable investment of capital resources and, as such, should be managed to get the best performance from the car and the best possible return on the investment of resources.

One of the first questions I ask race teams when I work with them is, "What is the most important adjustment on the car?" As you would expect, the variety of answers runs a full spectrum. The answer that ranks at or near the top with each of these impromptu surveys, right behind the driver, is tires. Tires are a critical component of any race car's ability to perform at or near its peak. The only physical interface between the car and the racetrack is the tires.

From the perspective of the Saturday night racer, tires, while important, may be only one of many different components that require a high level of dedicated attention. In addition, many Saturday night racers may not have a great deal of time to dedicate to the many factors competing for their time, especially when considering all of the other requirements to get the car to the track on a regular basis. The concept of tire management may not be something that gets any more attention than, say, engine maintenance or making sure the food gets loaded into the hauler for tonight's race. For many racers on a budget, just making sure they even have tires is more of a key factor than making sure the tires they have are in peak condition. While this attitude may not lead to many track championships, it is an understandable and reasonable mindset.

Within this discourse, we will be looking at dirt tires and focusing on Sprint cars. The fact of the matter is that cars racing on dirt have different types of issues from the cars that race on pavement. The type of tire, the compound, the size, and the brand to use are concerns the dirt racer may share with his or her pavement peers. The big difference is that this decision must be made at each corner of the car and not from an aggregate perspective, as it is with the pavement car. Many racing associations have specifications that may mandate the selection of all tires, or maybe just the right-rear tire. Even within the specification, there are many things still open for the racer to adjust and develop.

2/11This is a brand-new right-rear tire for a 410 non-wing Sprint car. You would think that it is ready to be used. It may be ready, but many racers and the manufacturer have some recommendations to further prepare this tire, depending on the car and the condition of the track.

Many racers may wish for all the new tires they could use. Yes, it would be nice to have new tires each race, but even in that scenario you still have to manage the use of the tires and determine the setup parameters of the tire and wheel combination. Even the solution with the highest cost requires a given level of work. In fact, the work load is even higher when the resources are richer.

Usually, in the forms of racing where this is the Standard Operating Procedure (SOP), such as NASCAR, IRL, and F1, the level of work does not diminish, it actually increases. There are other teams with the same SOP, and they are trying to get the most out of the tires, too-no different from the Saturday night racer. The only difference is they have teams of dedicated tire professionals who focus solely on tires and tire management.

It does not take a rocket scientist to determine that new tires are better than old ones. Short of getting new tires for every heat race and main event, what can you do to preserve tires and keep the level of performance as high as possible?

3/11The tire of the same style is grooved in preparation for a qualifying attempt. Notice the additional grooves across the blocks and the grooves emanating from the hole in the block.

The first step is to keep detailed notes. This is your first line of information gathering. You might be asking, how do I take notes, and what is important to document? Those are good questions. You can purchase a multitude of preprinted setup sheets from a variety of racing vendors. In fact, many of them are free! The issue is not so much the format but the fact that you are keeping notes. You most likely will develop a format that works for you over time, but in the beginning you need to keep track of a few things from a tire management perspective that may include but are not limited to the following: * Brand and compound number of tire* Tire age: The number of laps the tires have on them-You should be able to document the number of laps each tire in your inventory may have accumulated to date. If you race on a number of tracks of different sizes, you need to delineate the laps that were on a 11/42- and a 11/44-mile track. (Note: All tires have a serial number, a manufacturing date, or other unique identifier molded into the tire that will help you single them out. You can also mark each tire with your own identifying numbers and/or letters)* Individual tire setup-Tire width-Wheel width-The corner of the car on which the tire was mounted-Air pressure (cold and hot)-Circumference of the tire, pre- and post-race-Tire grooving (size of groove, pattern, and depth)* General condition of the tire, pre- and post-race-Are the edges sharp?-Is the tire feathered or blistered?-Tire temperatures after each run

4/11The difference in diameter from the right rear to the left rear shows the amount of stagger that is in this car to aid in getting it around the corner. Notice that only the left-rear tire on this Sprint car has additional grooving.

Creating a note sheet with each of the parameters you are tracking in a fill-in-the-blank type of format makes this data much easier to keep track of and much quicker to record. The easier and quicker it is to develop or execute, the more likely you can get the crew to accomplish the task. Racers are no different from other people in general. If it takes a great deal of effort to accomplish a given task, then the possibility is greater that the task will not be done. Make this task as easy as possible. You may even want to designate a person on your team who always has this responsibility, or rotate this job from race to race to develop your team. These note pages go into a master notebook you can refer to for future setup information.

This is something you can implement to develop the discipline required to keep track of the information. I have worked with several teams that keep this type of data, and it has helped them understand how the tires are performing. It also helps them keep a better level of control over the number of tires kept in their inventory. They know which ones to sell and which ones they should keep, and they know when new tires are required.

5/11This racer had a very good explanation for the grooving pattern on his tires. The center of the tire with the square grooves was to aid the tire down the straight, and the angled groove on the outside of the tire was to aid the tire in developing grip in the corners while the car was sideways. It must be working for him-he won three features last season.

Asking questions is another way to glean information. Your first resource is the manufacturer. Ask for suggested setups and check this information against your notes. Use this information to further improve your individual racing data bank, which includes wheel widths for a given tire and the recommended air pressure settings. Ask what the recommended tire temperatures are for the best performance and tire life. On the same thought, ask what temperatures are too high and, inversely, what temperatures are too low. The majority of the tire manufacturers have Web sites that explain and answer all of these questions.

Goodyear and Hoosier both have great Web sites for the dissemination of this type of information. Your next resource should be the dealers who are selling you tires. They want you to do well with their tires so that you continue buying more as the need arises. Look at what the other teams around you are doing. I am not suggesting stealing setup information. Rather, I am encouraging you to ask and learn. In general, racers are a helpful group until you start kicking their butts on the track-then, in their minds, you don't need help anymore.

Next, you have to learn to read your tires. They are telling you a story after each run; you just have to learn how to listen to what they are saying. The first thing you should be doing after every race is monitoring the air pressure. How much did the pressure rise from the setting at the start of the race? How much did the tire pressure grow in the trophy dash compared to the heat races and the main event?

Tires intended for Sprint cars running on dirt undergo some special preparation prior to hitting the track. The one preparation process that is unique although not limited to Sprint cars is grooving. It places a greater number of cutting edges into the tires to aid in gaining grip from the dirt surfaces on which they race.

The tires may come with a tread design, but the manufacturer cannot make a tire that will work on any track on any given night. This is an area where racers will be required to develop some extra knowledge to create a groove pattern that works for them. Many racers have developed groove patterns that work with wet, sticky tracks and groove patterns that help develop grip on dry, slick tracks.

The intent of grooving a tire is to increase the amount of square edges making contact with the track as the tire rotates, consequently developing more grip. Unfortunately, the tire doesn't usually travel with the track in a forward motion. Rather, when a Sprint car is sideways, as it so often is when entering or exiting a corner, it travels at various angles to the direction of travel. With the attitude the car assumes as it is being rotated through the corner, the tire is traveling as much sideways as it is forward. It is easy to see why many racers have developed groove patterns that run at angles to the tire's direction of rotation.

The grooving process is something that any racer can learn, and there are a good number of tools on the market that make it a very simple process. They range from a simple sharp razor-blade type of tool to heated knives. The heated knives or grooving irons are the logical choice for this process because they are faster and give you a greater level of control.

Weir Schankel, of Van Alstine Manufacturing, a maker of grooving tools, states, "The racers are asking for a tool that is easy to use and gives a professional result. Durability and adjustability are what the racer is demanding." Sprint car racers are using blades that range in width from 0.125, to 0.187, to 0.250 inch. The power required to run most grooving irons is no greater than what would be required to run a 31/48-inch electric drill motor. So you will not need to have a large-capacity generator to run a grooving iron at the track.

There are many tools on the market that will help you manage tires. These tools include air pressure gauges, tire tapes, and other tools for measuring the parameters that are important for good tire management. Measuring the outside circumference of the tires is critical. The difference in the diameter of the tires at each axle is called stagger, which helps turn the car. As the cars only turn left, and Sprint cars do not have differentials, the difference in the diameter of the right rear and the left rear helps turn the car. It is critical that you have a good way to get a quality measurement of this dimension.

There are multiple tools you can use for measuring a tire's temperature. Infrared tire pyrometers are very simple to use. You just point the gun at the surface you want to measure, pull the trigger, and the temperature shows up on a digital display on the gun. It is that simple. Tire pyrometers that use a probe that you actually press into the surface of the tire offer a digital display on the handheld unit that shows the temperature.

Of course, there is the old standby, which consists of just placing your hand on the tire and feeling the temperature. This is not a method I recommend, as it is just not that accurate, at least from a recording perspective, and there are limits. The threshold of human pain from heat is 140 degrees F. A higher temperature could burn your hand. (Tires can get as hot as 285 degrees F.)

Tire management is a rather basic process. The tools are not all that complex, and results can be incredibly profitable for you as a racer. Proper tire management could be the difference between winning and just being a participant. Tires will remain very important to the racer. Tire management is more than just buying new tires. You have to learn to manage this resource after the purchase so that you get the maximum value and speed from this important part of the race car.